The drugs which are used for the treatment of are bacterial meningitis are ampicillin, gentamycin, cefotaxime, and vancomycin HCL, where vancomycin HCL is broad spectrum antibiotic. There are various Nano particulate drug delivery systems such as dendrimers, lipoic nanoparticles, inorganic nanoparticles and polymeric nanoparticles capable of incorporating the therapeutic drugs or imaging agents with the effective drug targeting at required site in the body. The effective treatment and diagnosis of various CNS diseases is restricted by Blood–Brain Barrier (BBB) which inhibits almost all the macromolecular drugs as well as small-molecule drugs to permeate through brain. The direct drug delivery of drugs to brain may indicate higher therapeutic activity to toxicity ratio as that of systemic drug delivery. The intranasal drug delivery is the noninvasive method through which the drug can be delivered to brain through bypassing of BBB. The Nano particulate systems indicates the enhanced drug delivery to brain as compared to the drug solution formulation through avoidance of first-pass metabolism, rapid systemic absorption, fast onset of action, increased drug bioavailability and less systemic side effects etc. Moreover, chitosan based nanoparticles are also biodegradable and stable besides their muco-adhesive character and intrinsic bioactivity. This results in increased penetration of drugs in the brain through the olfactory route and therefore they can be used for the treatment of various CNS diseases.